Skip to content

K
Kernel

openeuler / Kernel
1 年多 前同步成功

通知 8
Star 0
Fork 0
K
Kernel
切换分支/标签
  1. 28 1月, 2021 1 次提交
    • H
      io_uring: fix flush cqring overflow list while TASK_INTERRUPTIBLE · 6195ba09
      由 Hao Xu 提交于 
      Abaci reported the follow warning:

[   27.073425] do not call blocking ops when !TASK_RUNNING; state=1 set at [] prepare_to_wait_exclusive+0x3a/0xc0
[   27.075805] WARNING: CPU: 0 PID: 951 at kernel/sched/core.c:7853 __might_sleep+0x80/0xa0
[   27.077604] Modules linked in:
[   27.078379] CPU: 0 PID: 951 Comm: a.out Not tainted 5.11.0-rc3+ #1
[   27.079637] Hardware name: Red Hat KVM, BIOS 0.5.1 01/01/2011
[   27.080852] RIP: 0010:__might_sleep+0x80/0xa0
[   27.081835] Code: 65 48 8b 04 25 80 71 01 00 48 8b 90 c0 15 00 00 48 8b 70 18 48 c7 c7 08 39 95 82 c6 05 f9 5f de 08 01 48 89 d1 e8 00 c6 fa ff  0b eb bf 41 0f b6 f5 48 c7 c7 40 23 c9 82 e8 f3 48 ec 00 eb a7
[   27.084521] RSP: 0018:ffffc90000fe3ce8 EFLAGS: 00010286
[   27.085350] RAX: 0000000000000000 RBX: ffffffff82956083 RCX: 0000000000000000
[   27.086348] RDX: ffff8881057a0000 RSI: ffffffff8118cc9e RDI: ffff88813bc28570
[   27.087598] RBP: 00000000000003a7 R08: 0000000000000001 R09: 0000000000000001
[   27.088819] R10: ffffc90000fe3e00 R11: 00000000fffef9f0 R12: 0000000000000000
[   27.089819] R13: 0000000000000000 R14: ffff88810576eb80 R15: ffff88810576e800
[   27.091058] FS:  00007f7b144cf740(0000) GS:ffff88813bc00000(0000) knlGS:0000000000000000
[   27.092775] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[   27.093796] CR2: 00000000022da7b8 CR3: 000000010b928002 CR4: 00000000003706f0
[   27.094778] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[   27.095780] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
[   27.097011] Call Trace:
[   27.097685]  __mutex_lock+0x5d/0xa30
[   27.098565]  ? prepare_to_wait_exclusive+0x71/0xc0
[   27.099412]  ? io_cqring_overflow_flush.part.101+0x6d/0x70
[   27.100441]  ? lockdep_hardirqs_on_prepare+0xe9/0x1c0
[   27.101537]  ? _raw_spin_unlock_irqrestore+0x2d/0x40
[   27.102656]  ? trace_hardirqs_on+0x46/0x110
[   27.103459]  ? io_cqring_overflow_flush.part.101+0x6d/0x70
[   27.104317]  io_cqring_overflow_flush.part.101+0x6d/0x70
[   27.105113]  io_cqring_wait+0x36e/0x4d0
[   27.105770]  ? find_held_lock+0x28/0xb0
[   27.106370]  ? io_uring_remove_task_files+0xa0/0xa0
[   27.107076]  __x64_sys_io_uring_enter+0x4fb/0x640
[   27.107801]  ? rcu_read_lock_sched_held+0x59/0xa0
[   27.108562]  ? lockdep_hardirqs_on_prepare+0xe9/0x1c0
[   27.109684]  ? syscall_enter_from_user_mode+0x26/0x70
[   27.110731]  do_syscall_64+0x2d/0x40
[   27.111296]  entry_SYSCALL_64_after_hwframe+0x44/0xa9
[   27.112056] RIP: 0033:0x7f7b13dc8239
[   27.112663] Code: 01 00 48 81 c4 80 00 00 00 e9 f1 fe ff ff 0f 1f 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05  3d 01 f0 ff ff 73 01 c3 48 8b 0d 27 ec 2c 00 f7 d8 64 89 01 48
[   27.115113] RSP: 002b:00007ffd6d7f5c88 EFLAGS: 00000286 ORIG_RAX: 00000000000001aa
[   27.116562] RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f7b13dc8239
[   27.117961] RDX: 000000000000478e RSI: 0000000000000000 RDI: 0000000000000003
[   27.118925] RBP: 00007ffd6d7f5cb0 R08: 0000000020000040 R09: 0000000000000008
[   27.119773] R10: 0000000000000001 R11: 0000000000000286 R12: 0000000000400480
[   27.120614] R13: 00007ffd6d7f5d90 R14: 0000000000000000 R15: 0000000000000000
[   27.121490] irq event stamp: 5635
[   27.121946] hardirqs last  enabled at (5643): [] console_unlock+0x5c4/0x740
[   27.123476] hardirqs last disabled at (5652): [] console_unlock+0x4e7/0x740
[   27.125192] softirqs last  enabled at (5272): [] __do_softirq+0x3c5/0x5aa
[   27.126430] softirqs last disabled at (5267): [] asm_call_irq_on_stack+0xf/0x20
[   27.127634] ---[ end trace 289d7e28fa60f928 ]---

This is caused by calling io_cqring_overflow_flush() which may sleep
after calling prepare_to_wait_exclusive() which set task state to
TASK_INTERRUPTIBLE
Reported-by: NAbaci <abaci@linux.alibaba.com>
Fixes: 6c503150 ("io_uring: patch up IOPOLL overflow_flush sync")
Reviewed-by: NPavel Begunkov <asml.silence@gmail.com>
Signed-off-by: NHao Xu <haoxu@linux.alibaba.com>
Signed-off-by: NJens Axboe <axboe@kernel.dk>
      6195ba09
  3. 27 1月, 2021 2 次提交
    • P
      io_uring: fix wqe->lock/completion_lock deadlock · 907d1df3
      由 Pavel Begunkov 提交于 
      Joseph reports following deadlock:

CPU0:
...
io_kill_linked_timeout  // &ctx->completion_lock
io_commit_cqring
__io_queue_deferred
__io_queue_async_work
io_wq_enqueue
io_wqe_enqueue  // &wqe->lock

CPU1:
...
__io_uring_files_cancel
io_wq_cancel_cb
io_wqe_cancel_pending_work  // &wqe->lock
io_cancel_task_cb  // &ctx->completion_lock

Only __io_queue_deferred() calls queue_async_work() while holding
ctx->completion_lock, enqueue drained requests via io_req_task_queue()
instead.

Cc: stable@vger.kernel.org # 5.9+
Reported-by: NJoseph Qi <joseph.qi@linux.alibaba.com>
Tested-by: NJoseph Qi <joseph.qi@linux.alibaba.com>
Signed-off-by: NPavel Begunkov <asml.silence@gmail.com>
Signed-off-by: NJens Axboe <axboe@kernel.dk>
      907d1df3
    • P
      io_uring: fix cancellation taking mutex while TASK_UNINTERRUPTIBLE · ca70f00b
      由 Pavel Begunkov 提交于 
      do not call blocking ops when !TASK_RUNNING; state=2 set at
	[<00000000ced9dbfc>] prepare_to_wait+0x1f4/0x3b0
	kernel/sched/wait.c:262
WARNING: CPU: 1 PID: 19888 at kernel/sched/core.c:7853
	__might_sleep+0xed/0x100 kernel/sched/core.c:7848
RIP: 0010:__might_sleep+0xed/0x100 kernel/sched/core.c:7848
Call Trace:
 __mutex_lock_common+0xc4/0x2ef0 kernel/locking/mutex.c:935
 __mutex_lock kernel/locking/mutex.c:1103 [inline]
 mutex_lock_nested+0x1a/0x20 kernel/locking/mutex.c:1118
 io_wq_submit_work+0x39a/0x720 fs/io_uring.c:6411
 io_run_cancel fs/io-wq.c:856 [inline]
 io_wqe_cancel_pending_work fs/io-wq.c:990 [inline]
 io_wq_cancel_cb+0x614/0xcb0 fs/io-wq.c:1027
 io_uring_cancel_files fs/io_uring.c:8874 [inline]
 io_uring_cancel_task_requests fs/io_uring.c:8952 [inline]
 __io_uring_files_cancel+0x115d/0x19e0 fs/io_uring.c:9038
 io_uring_files_cancel include/linux/io_uring.h:51 [inline]
 do_exit+0x2e6/0x2490 kernel/exit.c:780
 do_group_exit+0x168/0x2d0 kernel/exit.c:922
 get_signal+0x16b5/0x2030 kernel/signal.c:2770
 arch_do_signal_or_restart+0x8e/0x6a0 arch/x86/kernel/signal.c:811
 handle_signal_work kernel/entry/common.c:147 [inline]
 exit_to_user_mode_loop kernel/entry/common.c:171 [inline]
 exit_to_user_mode_prepare+0xac/0x1e0 kernel/entry/common.c:201
 __syscall_exit_to_user_mode_work kernel/entry/common.c:291 [inline]
 syscall_exit_to_user_mode+0x48/0x190 kernel/entry/common.c:302
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

Rewrite io_uring_cancel_files() to mimic __io_uring_task_cancel()'s
counting scheme, so it does all the heavy work before setting
TASK_UNINTERRUPTIBLE.

Cc: stable@vger.kernel.org # 5.9+
Reported-by: syzbot+f655445043a26a7cfab8@syzkaller.appspotmail.com
Signed-off-by: NPavel Begunkov <asml.silence@gmail.com>
[axboe: fix inverted task check]
Signed-off-by: NJens Axboe <axboe@kernel.dk>
      ca70f00b
  5. 26 1月, 2021 1 次提交
  7. 25 1月, 2021 5 次提交
    • J
      io_uring: only call io_cqring_ev_posted() if events were posted · b18032bb
      由 Jens Axboe 提交于 
      This normally doesn't cause any extra harm, but it does mean that we'll
increment the eventfd notification count, if one has been registered
with the ring. This can confuse applications, when they see more
notifications on the eventfd side than are available in the ring.

Do the nice thing and only increment this count, if we actually posted
(or even overflowed) events.
Reported-and-tested-by: NDan Melnic <dmm@fb.com>
Signed-off-by: NJens Axboe <axboe@kernel.dk>
      b18032bb
    • J
      io_uring: if we see flush on exit, cancel related tasks · 84965ff8
      由 Jens Axboe 提交于 
      Ensure we match tasks that belong to a dead or dying task as well, as we
need to reap those in addition to those belonging to the exiting task.

Cc: stable@vger.kernel.org # 5.9+
Reported-by: NJosef Grieb <josef.grieb@gmail.com>
Signed-off-by: NJens Axboe <axboe@kernel.dk>
      84965ff8
    • X
      proc_sysctl: fix oops caused by incorrect command parameters · 697edcb0
      由 Xiaoming Ni 提交于 
      The process_sysctl_arg() does not check whether val is empty before
invoking strlen(val).  If the command line parameter () is incorrectly
configured and val is empty, oops is triggered.

For example:
  "hung_task_panic=1" is incorrectly written as "hung_task_panic", oops is
  triggered. The call stack is as follows:
    Kernel command line: .... hung_task_panic
    ......
    Call trace:
    __pi_strlen+0x10/0x98
    parse_args+0x278/0x344
    do_sysctl_args+0x8c/0xfc
    kernel_init+0x5c/0xf4
    ret_from_fork+0x10/0x30

To fix it, check whether "val" is empty when "phram" is a sysctl field.
Error codes are returned in the failure branch, and error logs are
generated by parse_args().

Link: https://lkml.kernel.org/r/20210118133029.28580-1-nixiaoming@huawei.com
Fixes: 3db978d4 ("kernel/sysctl: support setting sysctl parameters from kernel command line")
Signed-off-by: NXiaoming Ni <nixiaoming@huawei.com>
Acked-by: NVlastimil Babka <vbabka@suse.cz>
Cc: Luis Chamberlain <mcgrof@kernel.org>
Cc: Kees Cook <keescook@chromium.org>
Cc: Iurii Zaikin <yzaikin@google.com>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Heiner Kallweit <hkallweit1@gmail.com>
Cc: Randy Dunlap <rdunlap@infradead.org>
Cc: <stable@vger.kernel.org>	[5.8+]
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      697edcb0
    • J
      io_uring: account io_uring internal files as REQ_F_INFLIGHT · 02a13674
      由 Jens Axboe 提交于 
      We need to actively cancel anything that introduces a potential circular
loop, where io_uring holds a reference to itself. If the file in question
is an io_uring file, then add the request to the inflight list.

Cc: stable@vger.kernel.org # 5.9+
Signed-off-by: NJens Axboe <axboe@kernel.dk>
      02a13674
    • P
      io_uring: fix sleeping under spin in __io_clean_op · 9d5c8190
      由 Pavel Begunkov 提交于 
      [   27.629441] BUG: sleeping function called from invalid context
	at fs/file.c:402
[   27.631317] in_atomic(): 1, irqs_disabled(): 1, non_block: 0,
	pid: 1012, name: io_wqe_worker-0
[   27.633220] 1 lock held by io_wqe_worker-0/1012:
[   27.634286]  #0: ffff888105e26c98 (&ctx->completion_lock)
	{....}-{2:2}, at: __io_req_complete.part.102+0x30/0x70
[   27.649249] Call Trace:
[   27.649874]  dump_stack+0xac/0xe3
[   27.650666]  ___might_sleep+0x284/0x2c0
[   27.651566]  put_files_struct+0xb8/0x120
[   27.652481]  __io_clean_op+0x10c/0x2a0
[   27.653362]  __io_cqring_fill_event+0x2c1/0x350
[   27.654399]  __io_req_complete.part.102+0x41/0x70
[   27.655464]  io_openat2+0x151/0x300
[   27.656297]  io_issue_sqe+0x6c/0x14e0
[   27.660991]  io_wq_submit_work+0x7f/0x240
[   27.662890]  io_worker_handle_work+0x501/0x8a0
[   27.664836]  io_wqe_worker+0x158/0x520
[   27.667726]  kthread+0x134/0x180
[   27.669641]  ret_from_fork+0x1f/0x30

Instead of cleaning files on overflow, return back overflow cancellation
into io_uring_cancel_files(). Previously it was racy to clean
REQ_F_OVERFLOW flag, but we got rid of it, and can do it through
repetitive attempts targeting all matching requests.
Reported-by: NAbaci <abaci@linux.alibaba.com>
Reported-by: NJoseph Qi <joseph.qi@linux.alibaba.com>
Cc: Xiaoguang Wang <xiaoguang.wang@linux.alibaba.com>
Signed-off-by: NPavel Begunkov <asml.silence@gmail.com>
Signed-off-by: NJens Axboe <axboe@kernel.dk>
      9d5c8190
  9. 23 1月, 2021 3 次提交
    • R
      cifs: do not fail __smb_send_rqst if non-fatal signals are pending · 214a5ea0
      由 Ronnie Sahlberg 提交于 
      RHBZ 1848178

The original intent of returning an error in this function
in the patch:
  "CIFS: Mask off signals when sending SMB packets"
was to avoid interrupting packet send in the middle of
sending the data (and thus breaking an SMB connection),
but we also don't want to fail the request for non-fatal
signals even before we have had a chance to try to
send it (the reported problem could be reproduced e.g.
by exiting a child process when the parent process was in
the midst of calling futimens to update a file's timestamps).

In addition, since the signal may remain pending when we enter the
sending loop, we may end up not sending the whole packet before
TCP buffers become full. In this case the code returns -EINTR
but what we need here is to return -ERESTARTSYS instead to
allow system calls to be restarted.

Fixes: b30c74c7 ("CIFS: Mask off signals when sending SMB packets")
Cc: stable@vger.kernel.org # v5.1+
Signed-off-by: NRonnie Sahlberg <lsahlber@redhat.com>
Reviewed-by: NPavel Shilovsky <pshilov@microsoft.com>
Signed-off-by: NSteve French <stfrench@microsoft.com>
      214a5ea0
    • P
      io_uring: fix short read retries for non-reg files · 9a173346
      由 Pavel Begunkov 提交于 
      Sockets and other non-regular files may actually expect short reads to
happen, don't retry reads for them. Because non-reg files don't set
FMODE_BUF_RASYNC and so it won't do second/retry do_read, we can filter
out those cases after first do_read() attempt with ret>0.

Cc: stable@vger.kernel.org # 5.9+
Suggested-by: NJens Axboe <axboe@kernel.dk>
Signed-off-by: NPavel Begunkov <asml.silence@gmail.com>
Signed-off-by: NJens Axboe <axboe@kernel.dk>
      9a173346
    • J
      io_uring: fix SQPOLL IORING_OP_CLOSE cancelation state · 607ec89e
      由 Jens Axboe 提交于 
      IORING_OP_CLOSE is special in terms of cancelation, since it has an
intermediate state where we've removed the file descriptor but hasn't
closed the file yet. For that reason, it's currently marked with
IO_WQ_WORK_NO_CANCEL to prevent cancelation. This ensures that the op
is always run even if canceled, to prevent leaving us with a live file
but an fd that is gone. However, with SQPOLL, since a cancel request
doesn't carry any resources on behalf of the request being canceled, if
we cancel before any of the close op has been run, we can end up with
io-wq not having the ->files assigned. This can result in the following
oops reported by Joseph:

BUG: kernel NULL pointer dereference, address: 00000000000000d8
PGD 800000010b76f067 P4D 800000010b76f067 PUD 10b462067 PMD 0
Oops: 0000 [#1] SMP PTI
CPU: 1 PID: 1788 Comm: io_uring-sq Not tainted 5.11.0-rc4 #1
Hardware name: Red Hat KVM, BIOS 0.5.1 01/01/2011
RIP: 0010:__lock_acquire+0x19d/0x18c0
Code: 00 00 8b 1d fd 56 dd 08 85 db 0f 85 43 05 00 00 48 c7 c6 98 7b 95 82 48 c7 c7 57 96 93 82 e8 9a bc f5 ff 0f 0b e9 2b 05 00 00 <48> 81 3f c0 ca 67 8a b8 00 00 00 00 41 0f 45 c0 89 04 24 e9 81 fe
RSP: 0018:ffffc90001933828 EFLAGS: 00010002
RAX: 0000000000000001 RBX: 0000000000000001 RCX: 0000000000000000
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 00000000000000d8
RBP: 0000000000000246 R08: 0000000000000001 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000
R13: 0000000000000000 R14: ffff888106e8a140 R15: 00000000000000d8
FS:  0000000000000000(0000) GS:ffff88813bd00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00000000000000d8 CR3: 0000000106efa004 CR4: 00000000003706e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 lock_acquire+0x31a/0x440
 ? close_fd_get_file+0x39/0x160
 ? __lock_acquire+0x647/0x18c0
 _raw_spin_lock+0x2c/0x40
 ? close_fd_get_file+0x39/0x160
 close_fd_get_file+0x39/0x160
 io_issue_sqe+0x1334/0x14e0
 ? lock_acquire+0x31a/0x440
 ? __io_free_req+0xcf/0x2e0
 ? __io_free_req+0x175/0x2e0
 ? find_held_lock+0x28/0xb0
 ? io_wq_submit_work+0x7f/0x240
 io_wq_submit_work+0x7f/0x240
 io_wq_cancel_cb+0x161/0x580
 ? io_wqe_wake_worker+0x114/0x360
 ? io_uring_get_socket+0x40/0x40
 io_async_find_and_cancel+0x3b/0x140
 io_issue_sqe+0xbe1/0x14e0
 ? __lock_acquire+0x647/0x18c0
 ? __io_queue_sqe+0x10b/0x5f0
 __io_queue_sqe+0x10b/0x5f0
 ? io_req_prep+0xdb/0x1150
 ? mark_held_locks+0x6d/0xb0
 ? mark_held_locks+0x6d/0xb0
 ? io_queue_sqe+0x235/0x4b0
 io_queue_sqe+0x235/0x4b0
 io_submit_sqes+0xd7e/0x12a0
 ? _raw_spin_unlock_irq+0x24/0x30
 ? io_sq_thread+0x3ae/0x940
 io_sq_thread+0x207/0x940
 ? do_wait_intr_irq+0xc0/0xc0
 ? __ia32_sys_io_uring_enter+0x650/0x650
 kthread+0x134/0x180
 ? kthread_create_worker_on_cpu+0x90/0x90
 ret_from_fork+0x1f/0x30

Fix this by moving the IO_WQ_WORK_NO_CANCEL until _after_ we've modified
the fdtable. Canceling before this point is totally fine, and running
it in the io-wq context _after_ that point is also fine.

For 5.12, we'll handle this internally and get rid of the no-cancel
flag, as IORING_OP_CLOSE is the only user of it.

Cc: stable@vger.kernel.org
Fixes: b5dba59e ("io_uring: add support for IORING_OP_CLOSE")
Reported-by: "Abaci <abaci@linux.alibaba.com>"
Reviewed-and-tested-by: NJoseph Qi <joseph.qi@linux.alibaba.com>
Signed-off-by: NJens Axboe <axboe@kernel.dk>
      607ec89e
  11. 22 1月, 2021 3 次提交
  13. 21 1月, 2021 1 次提交
  15. 18 1月, 2021 7 次提交
    • J
      btrfs: don't clear ret in btrfs_start_dirty_block_groups · 34d1eb0e
      由 Josef Bacik 提交于 
      If we fail to update a block group item in the loop we'll break, however
we'll do btrfs_run_delayed_refs and lose our error value in ret, and
thus not clean up properly.  Fix this by only running the delayed refs
if there was no failure.

CC: stable@vger.kernel.org # 4.4+
Reviewed-by: NQu Wenruo <wqu@suse.com>
Reviewed-by: NJohannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: NJosef Bacik <josef@toxicpanda.com>
Reviewed-by: NDavid Sterba <dsterba@suse.com>
Signed-off-by: NDavid Sterba <dsterba@suse.com>
      34d1eb0e
    • J
      btrfs: fix lockdep splat in btrfs_recover_relocation · fb286100
      由 Josef Bacik 提交于 
      While testing the error paths of relocation I hit the following lockdep
splat:

  ======================================================
  WARNING: possible circular locking dependency detected
  5.10.0-rc6+ #217 Not tainted
  ------------------------------------------------------
  mount/779 is trying to acquire lock:
  ffffa0e676945418 (&fs_info->balance_mutex){+.+.}-{3:3}, at: btrfs_recover_balance+0x2f0/0x340

  but task is already holding lock:
  ffffa0e60ee31da8 (btrfs-root-00){++++}-{3:3}, at: __btrfs_tree_read_lock+0x27/0x100

  which lock already depends on the new lock.

  the existing dependency chain (in reverse order) is:

  -> #2 (btrfs-root-00){++++}-{3:3}:
	 down_read_nested+0x43/0x130
	 __btrfs_tree_read_lock+0x27/0x100
	 btrfs_read_lock_root_node+0x31/0x40
	 btrfs_search_slot+0x462/0x8f0
	 btrfs_update_root+0x55/0x2b0
	 btrfs_drop_snapshot+0x398/0x750
	 clean_dirty_subvols+0xdf/0x120
	 btrfs_recover_relocation+0x534/0x5a0
	 btrfs_start_pre_rw_mount+0xcb/0x170
	 open_ctree+0x151f/0x1726
	 btrfs_mount_root.cold+0x12/0xea
	 legacy_get_tree+0x30/0x50
	 vfs_get_tree+0x28/0xc0
	 vfs_kern_mount.part.0+0x71/0xb0
	 btrfs_mount+0x10d/0x380
	 legacy_get_tree+0x30/0x50
	 vfs_get_tree+0x28/0xc0
	 path_mount+0x433/0xc10
	 __x64_sys_mount+0xe3/0x120
	 do_syscall_64+0x33/0x40
	 entry_SYSCALL_64_after_hwframe+0x44/0xa9

  -> #1 (sb_internal#2){.+.+}-{0:0}:
	 start_transaction+0x444/0x700
	 insert_balance_item.isra.0+0x37/0x320
	 btrfs_balance+0x354/0xf40
	 btrfs_ioctl_balance+0x2cf/0x380
	 __x64_sys_ioctl+0x83/0xb0
	 do_syscall_64+0x33/0x40
	 entry_SYSCALL_64_after_hwframe+0x44/0xa9

  -> #0 (&fs_info->balance_mutex){+.+.}-{3:3}:
	 __lock_acquire+0x1120/0x1e10
	 lock_acquire+0x116/0x370
	 __mutex_lock+0x7e/0x7b0
	 btrfs_recover_balance+0x2f0/0x340
	 open_ctree+0x1095/0x1726
	 btrfs_mount_root.cold+0x12/0xea
	 legacy_get_tree+0x30/0x50
	 vfs_get_tree+0x28/0xc0
	 vfs_kern_mount.part.0+0x71/0xb0
	 btrfs_mount+0x10d/0x380
	 legacy_get_tree+0x30/0x50
	 vfs_get_tree+0x28/0xc0
	 path_mount+0x433/0xc10
	 __x64_sys_mount+0xe3/0x120
	 do_syscall_64+0x33/0x40
	 entry_SYSCALL_64_after_hwframe+0x44/0xa9

  other info that might help us debug this:

  Chain exists of:
    &fs_info->balance_mutex --> sb_internal#2 --> btrfs-root-00

   Possible unsafe locking scenario:

	 CPU0                    CPU1
	 ----                    ----
    lock(btrfs-root-00);
				 lock(sb_internal#2);
				 lock(btrfs-root-00);
    lock(&fs_info->balance_mutex);

   *** DEADLOCK ***

  2 locks held by mount/779:
   #0: ffffa0e60dc040e0 (&type->s_umount_key#47/1){+.+.}-{3:3}, at: alloc_super+0xb5/0x380
   #1: ffffa0e60ee31da8 (btrfs-root-00){++++}-{3:3}, at: __btrfs_tree_read_lock+0x27/0x100

  stack backtrace:
  CPU: 0 PID: 779 Comm: mount Not tainted 5.10.0-rc6+ #217
  Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.13.0-2.fc32 04/01/2014
  Call Trace:
   dump_stack+0x8b/0xb0
   check_noncircular+0xcf/0xf0
   ? trace_call_bpf+0x139/0x260
   __lock_acquire+0x1120/0x1e10
   lock_acquire+0x116/0x370
   ? btrfs_recover_balance+0x2f0/0x340
   __mutex_lock+0x7e/0x7b0
   ? btrfs_recover_balance+0x2f0/0x340
   ? btrfs_recover_balance+0x2f0/0x340
   ? rcu_read_lock_sched_held+0x3f/0x80
   ? kmem_cache_alloc_trace+0x2c4/0x2f0
   ? btrfs_get_64+0x5e/0x100
   btrfs_recover_balance+0x2f0/0x340
   open_ctree+0x1095/0x1726
   btrfs_mount_root.cold+0x12/0xea
   ? rcu_read_lock_sched_held+0x3f/0x80
   legacy_get_tree+0x30/0x50
   vfs_get_tree+0x28/0xc0
   vfs_kern_mount.part.0+0x71/0xb0
   btrfs_mount+0x10d/0x380
   ? __kmalloc_track_caller+0x2f2/0x320
   legacy_get_tree+0x30/0x50
   vfs_get_tree+0x28/0xc0
   ? capable+0x3a/0x60
   path_mount+0x433/0xc10
   __x64_sys_mount+0xe3/0x120
   do_syscall_64+0x33/0x40
   entry_SYSCALL_64_after_hwframe+0x44/0xa9

This is straightforward to fix, simply release the path before we setup
the balance_ctl.

CC: stable@vger.kernel.org # 4.4+
Reviewed-by: NQu Wenruo <wqu@suse.com>
Reviewed-by: NJohannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: NJosef Bacik <josef@toxicpanda.com>
Reviewed-by: NDavid Sterba <dsterba@suse.com>
Signed-off-by: NDavid Sterba <dsterba@suse.com>
      fb286100
    • J
      btrfs: do not double free backref nodes on error · 49ecc679
      由 Josef Bacik 提交于 
      Zygo reported the following KASAN splat:

  BUG: KASAN: use-after-free in btrfs_backref_cleanup_node+0x18a/0x420
  Read of size 8 at addr ffff888112402950 by task btrfs/28836

  CPU: 0 PID: 28836 Comm: btrfs Tainted: G        W         5.10.0-e35f27394290-for-next+ #23
  Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.12.0-1 04/01/2014
  Call Trace:
   dump_stack+0xbc/0xf9
   ? btrfs_backref_cleanup_node+0x18a/0x420
   print_address_description.constprop.8+0x21/0x210
   ? record_print_text.cold.34+0x11/0x11
   ? btrfs_backref_cleanup_node+0x18a/0x420
   ? btrfs_backref_cleanup_node+0x18a/0x420
   kasan_report.cold.10+0x20/0x37
   ? btrfs_backref_cleanup_node+0x18a/0x420
   __asan_load8+0x69/0x90
   btrfs_backref_cleanup_node+0x18a/0x420
   btrfs_backref_release_cache+0x83/0x1b0
   relocate_block_group+0x394/0x780
   ? merge_reloc_roots+0x4a0/0x4a0
   btrfs_relocate_block_group+0x26e/0x4c0
   btrfs_relocate_chunk+0x52/0x120
   btrfs_balance+0xe2e/0x1900
   ? check_flags.part.50+0x6c/0x1e0
   ? btrfs_relocate_chunk+0x120/0x120
   ? kmem_cache_alloc_trace+0xa06/0xcb0
   ? _copy_from_user+0x83/0xc0
   btrfs_ioctl_balance+0x3a7/0x460
   btrfs_ioctl+0x24c8/0x4360
   ? __kasan_check_read+0x11/0x20
   ? check_chain_key+0x1f4/0x2f0
   ? __asan_loadN+0xf/0x20
   ? btrfs_ioctl_get_supported_features+0x30/0x30
   ? kvm_sched_clock_read+0x18/0x30
   ? check_chain_key+0x1f4/0x2f0
   ? lock_downgrade+0x3f0/0x3f0
   ? handle_mm_fault+0xad6/0x2150
   ? do_vfs_ioctl+0xfc/0x9d0
   ? ioctl_file_clone+0xe0/0xe0
   ? check_flags.part.50+0x6c/0x1e0
   ? check_flags.part.50+0x6c/0x1e0
   ? check_flags+0x26/0x30
   ? lock_is_held_type+0xc3/0xf0
   ? syscall_enter_from_user_mode+0x1b/0x60
   ? do_syscall_64+0x13/0x80
   ? rcu_read_lock_sched_held+0xa1/0xd0
   ? __kasan_check_read+0x11/0x20
   ? __fget_light+0xae/0x110
   __x64_sys_ioctl+0xc3/0x100
   do_syscall_64+0x37/0x80
   entry_SYSCALL_64_after_hwframe+0x44/0xa9
  RIP: 0033:0x7f4c4bdfe427

  Allocated by task 28836:
   kasan_save_stack+0x21/0x50
   __kasan_kmalloc.constprop.18+0xbe/0xd0
   kasan_kmalloc+0x9/0x10
   kmem_cache_alloc_trace+0x410/0xcb0
   btrfs_backref_alloc_node+0x46/0xf0
   btrfs_backref_add_tree_node+0x60d/0x11d0
   build_backref_tree+0xc5/0x700
   relocate_tree_blocks+0x2be/0xb90
   relocate_block_group+0x2eb/0x780
   btrfs_relocate_block_group+0x26e/0x4c0
   btrfs_relocate_chunk+0x52/0x120
   btrfs_balance+0xe2e/0x1900
   btrfs_ioctl_balance+0x3a7/0x460
   btrfs_ioctl+0x24c8/0x4360
   __x64_sys_ioctl+0xc3/0x100
   do_syscall_64+0x37/0x80
   entry_SYSCALL_64_after_hwframe+0x44/0xa9

  Freed by task 28836:
   kasan_save_stack+0x21/0x50
   kasan_set_track+0x20/0x30
   kasan_set_free_info+0x1f/0x30
   __kasan_slab_free+0xf3/0x140
   kasan_slab_free+0xe/0x10
   kfree+0xde/0x200
   btrfs_backref_error_cleanup+0x452/0x530
   build_backref_tree+0x1a5/0x700
   relocate_tree_blocks+0x2be/0xb90
   relocate_block_group+0x2eb/0x780
   btrfs_relocate_block_group+0x26e/0x4c0
   btrfs_relocate_chunk+0x52/0x120
   btrfs_balance+0xe2e/0x1900
   btrfs_ioctl_balance+0x3a7/0x460
   btrfs_ioctl+0x24c8/0x4360
   __x64_sys_ioctl+0xc3/0x100
   do_syscall_64+0x37/0x80
   entry_SYSCALL_64_after_hwframe+0x44/0xa9

This occurred because we freed our backref node in
btrfs_backref_error_cleanup(), but then tried to free it again in
btrfs_backref_release_cache().  This is because
btrfs_backref_release_cache() will cycle through all of the
cache->leaves nodes and free them up.  However
btrfs_backref_error_cleanup() freed the backref node with
btrfs_backref_free_node(), which simply kfree()d the backref node
without unlinking it from the cache.  Change this to a
btrfs_backref_drop_node(), which does the appropriate cleanup and
removes the node from the cache->leaves list, so when we go to free the
remaining cache we don't trip over items we've already dropped.

Fixes: 75bfb9af ("Btrfs: cleanup error handling in build_backref_tree")
CC: stable@vger.kernel.org # 4.4+
Signed-off-by: NJosef Bacik <josef@toxicpanda.com>
Reviewed-by: NDavid Sterba <dsterba@suse.com>
Signed-off-by: NDavid Sterba <dsterba@suse.com>
      49ecc679
    • J
      btrfs: don't get an EINTR during drop_snapshot for reloc · 18d3bff4
      由 Josef Bacik 提交于 
      This was partially fixed by f3e3d9cc ("btrfs: avoid possible signal
interruption of btrfs_drop_snapshot() on relocation tree"), however it
missed a spot when we restart a trans handle because we need to end the
transaction.  The fix is the same, simply use btrfs_join_transaction()
instead of btrfs_start_transaction() when deleting reloc roots.

Fixes: f3e3d9cc ("btrfs: avoid possible signal interruption of btrfs_drop_snapshot() on relocation tree")
CC: stable@vger.kernel.org # 5.4+
Signed-off-by: NJosef Bacik <josef@toxicpanda.com>
Reviewed-by: NDavid Sterba <dsterba@suse.com>
Signed-off-by: NDavid Sterba <dsterba@suse.com>
      18d3bff4
    • L
      udf: fix the problem that the disc content is not displayed · 5cdc4a69
      由 lianzhi chang 提交于 
      When the capacity of the disc is too large (assuming the 4.7G
specification), the disc (UDF file system) will be burned
multiple times in the windows (Multisession Usage). When the
remaining capacity of the CD is less than 300M (estimated
value, for reference only), open the CD in the Linux system,
the content of the CD is displayed as blank (the kernel will
say "No VRS found"). Windows can display the contents of the
CD normally.
Through analysis, in the "fs/udf/super.c": udf_check_vsd
function, the actual value of VSD_MAX_SECTOR_OFFSET may
be much larger than 0x800000. According to the current code
logic, it is found that the type of sbi->s_session is "__s32",
 when the remaining capacity of the disc is less than 300M
(take a set of test values: sector=3154903040,
sbi->s_session=1540464, sb->s_blocksize_bits=11 ), the
calculation result of "sbi->s_session << sb->s_blocksize_bits"
 will overflow. Therefore, it is necessary to convert the
type of s_session to "loff_t" (when udf_check_vsd starts,
assign a value to _sector, which is also converted in this
way), so that the result will not overflow, and then the
content of the disc can be displayed normally.

Link: https://lore.kernel.org/r/20210114075741.30448-1-changlianzhi@uniontech.comSigned-off-by: Nlianzhi chang <changlianzhi@uniontech.com>
Signed-off-by: NJan Kara <jack@suse.cz>
      5cdc4a69
    • J
      fs/cifs: Simplify bool comparison. · 16a78851
      由 Jiapeng Zhong 提交于 
      Fix the follow warnings:

./fs/cifs/connect.c: WARNING: Comparison of 0/1 to bool variable
Reported-by: NAbaci Robot <abaci@linux.alibaba.com>
Signed-off-by: NJiapeng Zhong <abaci-bugfix@linux.alibaba.com>
Signed-off-by: NSteve French <stfrench@microsoft.com>
      16a78851
    • J
      fs/cifs: Assign boolean values to a bool variable · 2be449fc
      由 Jiapeng Zhong 提交于 
      Fix the following coccicheck warnings:

./fs/cifs/connect.c:3386:2-21: WARNING: Assignment of 0/1 to
bool variable.
Reported-by: NAbaci Robot <abaci@linux.alibaba.com>
Signed-off-by: NJiapeng Zhong <abaci-bugfix@linux.alibaba.com>
Signed-off-by: NSteve French <stfrench@microsoft.com>
      2be449fc
  17. 17 1月, 2021 6 次提交
    • P
      io_uring: fix skipping disabling sqo on exec · 0b5cd6c3
      由 Pavel Begunkov 提交于 
      If there are no requests at the time __io_uring_task_cancel() is called,
tctx_inflight() returns zero and and it terminates not getting a chance
to go through __io_uring_files_cancel() and do
io_disable_sqo_submit(). And we absolutely want them disabled by the
time cancellation ends.
Reported-by: NJens Axboe <axboe@kernel.dk>
Signed-off-by: NPavel Begunkov <asml.silence@gmail.com>
Fixes: d9d05217 ("io_uring: stop SQPOLL submit on creator's death")
Signed-off-by: NJens Axboe <axboe@kernel.dk>
      0b5cd6c3
    • P
      io_uring: fix uring_flush in exit_files() warning · 4325cb49
      由 Pavel Begunkov 提交于 
      WARNING: CPU: 1 PID: 11100 at fs/io_uring.c:9096
	io_uring_flush+0x326/0x3a0 fs/io_uring.c:9096
RIP: 0010:io_uring_flush+0x326/0x3a0 fs/io_uring.c:9096
Call Trace:
 filp_close+0xb4/0x170 fs/open.c:1280
 close_files fs/file.c:401 [inline]
 put_files_struct fs/file.c:416 [inline]
 put_files_struct+0x1cc/0x350 fs/file.c:413
 exit_files+0x7e/0xa0 fs/file.c:433
 do_exit+0xc22/0x2ae0 kernel/exit.c:820
 do_group_exit+0x125/0x310 kernel/exit.c:922
 get_signal+0x3e9/0x20a0 kernel/signal.c:2770
 arch_do_signal_or_restart+0x2a8/0x1eb0 arch/x86/kernel/signal.c:811
 handle_signal_work kernel/entry/common.c:147 [inline]
 exit_to_user_mode_loop kernel/entry/common.c:171 [inline]
 exit_to_user_mode_prepare+0x148/0x250 kernel/entry/common.c:201
 __syscall_exit_to_user_mode_work kernel/entry/common.c:291 [inline]
 syscall_exit_to_user_mode+0x19/0x50 kernel/entry/common.c:302
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

An SQPOLL ring creator task may have gotten rid of its file note during
exit and called io_disable_sqo_submit(), but the io_uring is still left
referenced through fdtable, which will be put during close_files() and
cause a false positive warning.

First split the warning into two for more clarity when is hit, and the
add sqo_dead check to handle the described case.

Reported-by: syzbot+a32b546d58dde07875a1@syzkaller.appspotmail.com
Signed-off-by: NPavel Begunkov <asml.silence@gmail.com>
Signed-off-by: NJens Axboe <axboe@kernel.dk>
      4325cb49
    • P
      io_uring: fix false positive sqo warning on flush · 6b393a1f
      由 Pavel Begunkov 提交于 
      WARNING: CPU: 1 PID: 9094 at fs/io_uring.c:8884
	io_disable_sqo_submit+0x106/0x130 fs/io_uring.c:8884
Call Trace:
 io_uring_flush+0x28b/0x3a0 fs/io_uring.c:9099
 filp_close+0xb4/0x170 fs/open.c:1280
 close_fd+0x5c/0x80 fs/file.c:626
 __do_sys_close fs/open.c:1299 [inline]
 __se_sys_close fs/open.c:1297 [inline]
 __x64_sys_close+0x2f/0xa0 fs/open.c:1297
 do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

io_uring's final close() may be triggered by any task not only the
creator. It's well handled by io_uring_flush() including SQPOLL case,
though a warning in io_disable_sqo_submit() will fallaciously fire by
moving this warning out to the only call site that matters.

Reported-by: syzbot+2f5d1785dc624932da78@syzkaller.appspotmail.com
Signed-off-by: NPavel Begunkov <asml.silence@gmail.com>
Signed-off-by: NJens Axboe <axboe@kernel.dk>
      6b393a1f
    • J
      io_uring: iopoll requests should also wake task ->in_idle state · c93cc9e1
      由 Jens Axboe 提交于 
      If we're freeing/finishing iopoll requests, ensure we check if the task
is in idling in terms of cancelation. Otherwise we could end up waiting
forever in __io_uring_task_cancel() if the task has active iopoll
requests that need cancelation.

Cc: stable@vger.kernel.org # 5.9+
Signed-off-by: NJens Axboe <axboe@kernel.dk>
      c93cc9e1
    • L
      mm: don't play games with pinned pages in clear_page_refs · 9348b73c
      由 Linus Torvalds 提交于 
      Turning a pinned page read-only breaks the pinning after COW.  Don't do it.

The whole "track page soft dirty" state doesn't work with pinned pages
anyway, since the page might be dirtied by the pinning entity without
ever being noticed in the page tables.
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      9348b73c
    • L
      mm: fix clear_refs_write locking · 29a951df
      由 Linus Torvalds 提交于 
      Turning page table entries read-only requires the mmap_sem held for
writing.

So stop doing the odd games with turning things from read locks to write
locks and back.  Just get the write lock.
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      29a951df
  19. 16 1月, 2021 6 次提交
  21. 14 1月, 2021 5 次提交